This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A340384 #15 Jan 16 2021 06:40:02 %S A340384 42,70,154,176,182,238,266,322,406,434,518,574,602,658,742,826,854, %T A340384 938,994,1022,1106,1162,1246,1250,1358,1414,1442,1498,1526,1582,1664, %U A340384 1778,1834,1918,1946,2086,2114,2198,2282,2338,2422,2506,2534,2674,2702,2758,2786,2954,3122,3178,3206,3262,3346,3374,3514,3598 %N A340384 Positions of seventeens in A340094, the Dirichlet inverse of f(n) = n - phi(n) + 1. %C A340384 These terms correspond to the horizontal line shown above the X-axis in the logarithmic scatter plots of A340094. %C A340384 The only non-multiples of 7 among the first 13832 terms are 176, 1250, 1664. Apart from such exceptions (are there more?), all other terms are of the form 2*7*p, with p running through all odd primes in A065091 \ {7}. %H A340384 Antti Karttunen, <a href="/A340384/b340384.txt">Table of n, a(n) for n = 1..13832; all terms < 2^21</a> %F A340384 {n such that A340094(n) = 17}. %o A340384 (PARI) isA340384(n) = (17==A340094(n)); %Y A340384 Cf. A065091, A340094. %K A340384 nonn %O A340384 1,1 %A A340384 _Antti Karttunen_, Jan 07 2021